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v6en
Wednesday 25th May 2005, 11:19
Road legal semi slick tyres?

if so, any good as i'm considering trying some for the 1/4 mile. so if anyone's had the experience let's hear ya :)

jacq.

Wobbly Dave
Wednesday 25th May 2005, 11:23
I asked Hamish this very question and he said dont, not unless you are willing to sacrifice my car (transmission) to go all out for the win. He has a point. It might be that I am on the limit of what my car will do. So you might be OK. There again your car might go bang?

Mrsmopp
Wednesday 25th May 2005, 11:28
Dave can you give us a bit more info as to why a car might go bang with semi slicks on?

x

Wobbly Dave
Wednesday 25th May 2005, 11:40
My car is hard tuned - to about the limits of what it will do. There is a limit to where I can go now with the engine as it stands. It has been safely tuned with the traction of road tyres. Semi-slicks will give me far better grip on a 1/4 than standard road tyres. This means that there will be an additional load/strain on the parts just cos the tyre traction is increased - Newton's 3rd Law of Motion, i.e. for every action there is an equal an opposite reaction.

To be honest I am not willing to take the risk by employing "possibly" destructive lengths just to be the fastest on the day. It is after all, my road/daily car. I would have to stop caring if the car* blew up or not, to go all out for the win. I care too much so I wont.

However if I had less tune e.g. RICA stage 1, and wasnt quite as close to the reliability boundary on the internals - slicks wouldn't be an issue, as you are not taking those components over the limit.


*most likely the transmission

M44K TS
Wednesday 25th May 2005, 13:38
A mate of mine has semi slicks for track use on his 106 Rallye (quick a quick lillte car and corners as if it were on rails) they are great for track/1/4 mile use but on the road, they wear out too quick due to them having a softer compound.

After_Shock
Wednesday 25th May 2005, 14:14
I had semi's on the C70 best thing I ever bought for the car,obviously couldnt use the car in the wet but stunning in the dry.

Im sorry dave but what you have been told makes virtually no sense at all, a tyre destroying a perfectly well tuned road car!

After_Shock
Wednesday 25th May 2005, 14:15
Mark your mates 106 isnt a bright solid blue colour that hangs around with a silver FTO by any chance??

p fandango
Wednesday 25th May 2005, 16:49
i've got 2 spare T-5 rims, just waiting till i have some spare pennies to buy total slicks :sinner:

After_Shock
Wednesday 25th May 2005, 16:50
Naughty naughty, cant use those on the public highway!

p fandango
Wednesday 25th May 2005, 16:54
Naughty naughty, cant use those on the public highway!
wouldn't dream of it officer, purely for the quarter mile :shifty:

After_Shock
Wednesday 25th May 2005, 16:56
Good to hear, unless of course its dark and dry and you fancy trying them out!

p fandango
Wednesday 25th May 2005, 17:07
but it would be alot easier to fit the slicks at home than once at the track, saves me having 2 spares rolling around in the boot when i race aswell :bud:

M44K TS
Wednesday 25th May 2005, 18:09
Mark your mates 106 isnt a bright solid blue colour that hangs around with a silver FTO by any chance??

it's one of my mates yes, (Andy Snailham) but not the one that had the cut slicks, (iatleast i think it wasn't)

And yeah, the guy with the FTO is another mate of mine

After_Shock
Wednesday 25th May 2005, 18:14
I only ask as went to a cruise quite a while back now in the C70 and was parked up with a few mates and a blue 106 rallye and a Silver FTO were driving around the car park for ages however slowed down to a crawl everytime passed me and my mates, then as we left the 106 and the FTO conveniently followed through the roads in Durham onto the A1 and things got a bit silly speed wise!

M44K TS
Wednesday 25th May 2005, 18:19
that sounds like them 2, the guy with the 106 was in court today for speeding.

Where abouts were you when you seen them?

After_Shock
Wednesday 25th May 2005, 18:25
The car park was at the Arniston centre, then they followed out onto the A1 and followed me off the A1 towards the Tyne Tunnel, dont know what the road is called.

They stayed behind at first until the last stretch of dual carriageway were the chester le street round about is then they both overtook so I gave chase up the slip road onto the A1 and overtook both of them, however I slowed at they both came back for another go so I left them standing again and then they backed off, however when I took the tyne tunnel turn off I saw both their headlights lift up in the distance and they had a long run at me. The 106 pulled up alongside at about 130mph at which point I changed into 5th gear and left him again but slowed right down as didnt want to loose my liscence!

Was good fun in a way, just wanted too happy with the way they kept slowing down when driving past in the car park was a bit weird.

v6en
Wednesday 25th May 2005, 20:49
Well thanks for the replies, i'm not worried so much about the engine as the driveshafts, or i wasn't anyway lol. will let you know how it gets on.

jacq.

Ross9
Wednesday 25th May 2005, 21:06
Hmm, never heard of tyres killing engines before, I see the theory, but if somethings going to go it'll be driveshafts, cv's, gearbox, clutch etc, drivetrain takes the strain of the tyres not slipping as much.

I find it hard to accept an engine could be tuned to the point where simply getting traction would pop it, each to their own opinion though.

Will see how we get on.

Ross

After_Shock
Wednesday 25th May 2005, 21:07
Sorry for going off topic however getting back on topic, try them if your wanting to try the 1/4mile of want that extra grip on the front end.

The front tyres having extra grip will have no adverse effects on your engine or driveshafts or anything else for that matter, if anything the extra grip will reduce wheelspin and prevent as many vibrations going through the drivetrain theirfore probably protecting it more than on normal tyres, with regards to the engine they have the same rev limit regardless whether on slicks or not so I have no idea how having more grip can threaten that either!

Wobbly Dave
Thursday 26th May 2005, 02:17
Maybe I am wrong, but I'd rather not take the risk. To be fair I never actually specified which bit. I have been back and edited and I agree with Ross9 - it would most likely be driveshafts, diff or tranny.

After_Shock
Thursday 26th May 2005, 08:29
Thats the thing hows their a risk!? It makes no sense at all, if theirs more grip its going to protect things more, as I said the engines have exactly the same rev limit regardless of tyres.

F1 engines are amongst the highest strung in the world but use probably the stickiest tyres in the world and if that theory is true why are they not all running around on £75 Falkens to protect their engines? (major exageration I know).

Wobbly Dave
Friday 27th May 2005, 10:28
I never actually said engine and even so it has nothing to do with the rev limit, in my mind.

It is not just that bit that has to deal with the power. What's right for me may not apply to others.

After_Shock
Friday 27th May 2005, 10:30
The C70 was almost identical to the spec your running now so that was on the edge aswell however that ran slicks for a good while without a problem, ive tried looking at it from a few angles and I still cant see how it would push anything over the edge or put anything at risk!

pyrotechnictigger
Friday 27th May 2005, 10:46
The theory is sound. Once the engine pushes over the grip level of the tyre, the grip is releases as a function of spin. Acts like a safety valve. If the tyres dont spin, the drive train as a whole is under max possible load. The more torque the engine generates, the more load on the drive train. Whether its enough to break anything is a different matter, but it is theoretically sound. If not spelt correctly :slap:

Thats my 100th post BTW:)

After_Shock
Friday 27th May 2005, 11:00
Well done on the 100th!

True but as you say how could that damage the car and if the car is that fragile that it could be caused to break simply because of tyres they shouldnt be tuned to that level.

But what happens when the car has less grippy tyres on and constant wheelspin is happening, that will put more stress on the components than actually having the grip?

pyrotechnictigger
Friday 27th May 2005, 11:07
Nah because the engine is running free with much less load.

After_Shock
Friday 27th May 2005, 11:11
First time ive heard of grip being a bad thing, starting to see were your coming from but if things are that fragile the cars shouldnt be running so close to the limit, personally if it was that close I think it would break either way as eventually less grippy tyres will get grip and increase the load.

Also whats the point in having the power if you cant actually use it as with that theory having the grip to get the power down the car will get damaged.

Ross9
Friday 27th May 2005, 21:53
Theory is that in the lower gears where the torque forces are stronger on the car the tyres slip and let it dissapate, higher gears the force on the shafts etc is less at the same rpm and boost so it dsoesnt matter that its gripping now.

I read Daves original post as he was saying the engine could break as it was tuned to the "edge" and the tyres gripping and increasing load woul dbreak it. Which I fin dhighly doubtful

I think what he actually meant was that the power output of his car is enough to warp a shaft, break a cv etc if the tyres gripped. Which can happen, but I would be surprised if it were to occur.

I'm pretty sure the T4 will be fine and dandy.

Ross

JUDGENINJA
Saturday 28th May 2005, 00:37
I asked the same question to a tyre specialist after I ask to price up a set of slicks for my two spares in preparation of Avon Park earlier this year. The response I got from him was "DON'T DO IT, you'll damage your car" ...
This made me curious to find out why...

Basically the interpretation I made was :
the engine transfers all it's power to the clutch...
which then transfers power to the gearbox...
which then transfers the power to the driveshafts...
which then transfers power the wheels.
In return the increased grip level of a slick tyre would transfer alot of the stresses back up the drivetrain system

Which component actually gives way first would be down in the lap of the gods, but which ever weak link your car has it would find it.

I wouldn't say don't do it, but if you do beware of the possible consequences it may cause....

Ross9
Saturday 28th May 2005, 00:52
Yeah, sound theory, exactly the way I see it. reckon al will be fine at jacqs spec though.

Only semi-slicks as well, full slicks are cheating, if its not road legal then its a competition car, which is a whole different ball game and not comparable.

Ross

Wobbly Dave
Saturday 28th May 2005, 23:49
All I was trying to say was that it was important to know where the limits are. I was trying to point out that increasing the traction puts additional load on the transmission and engine. It has to. Newton says so! As to whether you approach the braking load of those components is another thing. I was just erring on the side of caution.

If you will allow me a small degree of latitude...
It is the same for any modification. Jamie's T4 engine went bang when he put NOS on it. Hamish bent rods on Adam's ex-850R.

If Hamish and Judge's tyre expert have said similar things - then I think there maybe something to bear in mind. That's all!

madness
Sunday 29th May 2005, 21:44
hey! i only bent 1 rod :troutslap

as i mentioned to ross i am using toyo r888's now which are road legal and i have found them really good. but- it needs to be a hot day. on a semi warm/cold day normal road tyres are better.

i dont think @ the spec any of our cars have anything would go apart from a driveshaft - they are the known weak point and i have spares in the shed !!!

Ross9
Monday 30th May 2005, 15:34
Lol, well they didn't make much difference to my latest run up the 1/4 mile i must say, managed pretty much the same as last time i was there, thankfully no loss of drive shafts clutch or gearbox noted. looks like even though the car is more powerful, it has still reached the threshold of its current spec and will take an almighty shove to get it past 14.2 and 2.3 secs 60ft.
thanks for the replies though folks.

jacq.

madness
Tuesday 31st May 2005, 13:22
ross, when they were doing the 24 hr s60 touring races they had to tape in the car 2 spare driveshafts , as all spares had to be carried and reliability on them was questionable to say the least !!!!!!!!!!!
we have had a few go on standard cars in the workshop , hence my preperation with the spares.